"The most beautiful, compelling film ever made that has a farting dog."

What possesses a man to make a movie that could be described as "Amelie" meets "Cold Mountain," a film both whimsical and devastating in its depiction of war? And more to the point, how does a man so possessed manage to make it work?

French director Jean-Pierre Jeunet reunites with his "Amelie" star Audrey Tautou in "A Very Long Engagement," and it may be the best film he's ever made. It spotlights the absurdity of war along with its brutality, and underscores the indomitability of the human spirit with a "love conquers all" story line of uncommon poignance. It also has a farting dog and a woman who says "Doggie fart, gladdens my heart" every time. So you see what we're dealing with here.

Tautou plays Mathilde, a girl of Amelie-esque mirthfulness encumbered by the travails of her life. Her parents dead, she lives with her kindly aunt and uncle on a farm in rural France, and she walks with a limp as a result of childhood polio. Her lifelong love Maneche (Gaspard Ulliel) has not been heard from since he was court-martialed three years ago, near the end of World War I. The court martial was for self-mutilation: He intentionally got shot in the hand in order to be sent home to his beloved. Four other men were charged for nearly identical crimes, all with injuries to their right hands. One of the men received his injury accidentally, using his gun to hit a rat that was scampering around his bed.

The men were sentenced to death, but officers either lazy or cruel chose to execute them by sending them out into No-Man's-Land and letting them fend for themselves. Neither Mathilde nor anyone else -- including the viewer -- knows for sure whether any of the five survived. Mathilde is convinced she would know instinctively if Maneche were dead. But if he's alive, where is he?

Mathilde hires a private investigator named Germain Pire (Ticky Holgado) who, like everyone else in the film, is a cutely idiosyncratic character, to look for information about Maneche's fate. Pire finds witnesses and survivors from the particular trench that was the site of Maneche's sentencing, but not many, and none with much information. Meanwhile, a woman named Tina Lombardi (Marion Cotillard), whore and girlfriend of a Corsican man who was among the five court-martialed, is finding officers responsible for her lover's death and executing them herself in cruelly ingenious fashions appropriate to the occasion. War begets war, as you know.

Jeunet, who adapted the screenplay with regular writing partner Guillaume Laurant from Sebastien Japrisot's novel, gives us just enough flashbacks to Mathilde and Maneche's pre-war life to suggest the urgency and romanticism of their relationship. Her love for him has not faded in the intervening years, despite having had no word from him. Her apparent belief is that if he is alive, he still loves her. No other scenario occurs to her as a possibility.

Yet despite her head-in-the-clouds romanticism, she behaves with a certain pragmatism, too. She cannot travel the way her P.I. can, but she still finds clues in letters and belongings left behind by the five condemned soldiers. By learning more about them, she reasons, she can find out what happened to Maneche. If one of the five survived, then maybe Maneche did, too.

Because of this, we meet the families and loved ones of Maneche's fellow soldiers, all with compelling stories of love, loss and tragedy. For example, there is Elodie Gordes (Jodie Foster), wife of Benjamin Gordes (Jean-Pierre Darroussin). Benjamin was infertile, but the pair had five children from previous marriages and adoptions. Gordes knew that if they had a sixth, the army would send him home. He asked his friend Bastoche (Jerome Kircher) to impregnate Elodie for him. Heartbreak and sorrow followed. Jodie Foster, speaking French like a native, performs as beautifully and passionately as she does in English, lending the film more gravitas and emotion.

Between her breakthrough performance as Amelie and this one, Tautou has come to embody impish optimism, so much that if you Google "Audrey Tautou" and "gamine," you will get nearly 500 hits. Though there is much sadness in "A Very Long Engagement," there is also a driving, underlying sense of hope. It is a powerful, sweet film.